Credit: The Associated Press

Former Olympic and world swimming champion Michael Phelps of the US attends the unveiling of a mosaic installed in his honour at the FINA Swimming World Championships in Barcelona, Spain, Sunday, July 28, 2013 .

BARCELONA, Spain — Michael Phelps keeps saying he has no plans for a swimming comeback. Yet he's leaving the door open to change his mind in time for the 2016 Olympics.

As Phelps puts it, "I don't know what I'm doing tomorrow."

Phelps spoke Monday in Barcelona to The Associated Press and other international media organizations in a series of one-on-one interviews set up by sponsor Speedo.